Add images

Fuck PDF/A. Can not convert with `epstopdf`, but re-saving in Inkscape
worked.

en/intro.tex

@@ -79,19 +79,21 @@ Figure~\ref{fig:basic-icons}.
 
 \begin{figure}[h]
 	\centering
-	\begin{subfigure}[b]{0.3\textwidth}
+	\begin{subfigure}[b]{0.25\textwidth}
 		\centering
-		\X{Router}
+		\includegraphics[width=0.6\textwidth]{../img/router.pdf}
 		\caption*{Router}
 	\end{subfigure}
-	\begin{subfigure}[b]{0.3\textwidth}
+	\hfil
+	\begin{subfigure}[b]{0.25\textwidth}
 		\centering
-		\X{Network}
+		\includegraphics[width=0.6\textwidth]{../img/cloud.pdf}
 		\caption*{Network}
 	\end{subfigure}
-	\begin{subfigure}[b]{0.3\textwidth}
+	\hfil
+	\begin{subfigure}[b]{0.25\textwidth}
 		\centering
-		\X{Switch}
+		\includegraphics[width=0.6\textwidth]{../img/workgroup-switch.pdf}
 		\caption*{Switch}
 	\end{subfigure}
 	\caption{Basic Cisco network icons}